{
  "abstract": "We present time-series observations of the long period comet C/2025 K1 (ATLAS) obtained in 2025-2026, bracketing the comet's fragmentation in early November 2025. We show that a simple radiation pressure model can explain many of the comet's properties: the rapid fading after fragmentation, the increasing mean particle size in the projected photometry aperture, and the time dependence of the surface brightness profile. Small dust particles ($\\lesssim 100 μ$m) dominate the coma, with average dust velocity $\\sim$ a few $\\times$ 1 meter s$^{-1}$. The nucleus radius is estimated at $\\sim$0.5 km and the dust properties are consistent with, but do not prove, an origin in nucleus rotational breakup, followed by being swept down the tail by radiation pressure.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.34558",
  "author_total": 2,
  "authors": [
    {
      "name": "Jane Luu"
    },
    {
      "name": "David Jewitt"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/3zxytsrcf0fdy.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.34558",
  "fulltext_url": null,
  "id": "3zxytsrcf0fdy",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.34558",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "astro-ph.EP"
    ],
    [
      "arxiv",
      "astro-ph.GA"
    ],
    [
      "openalex",
      "3103|Astro and Planetary Science"
    ]
  ],
  "openalex": "W7223963796",
  "pdf_url": "https://arxiv.org/pdf/2610.34558",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-25",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/3zxytsrcf0fdy.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:35:35Z",
      "native_id": "2610.34558",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.34558"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.GA",
      "subfield": "galaxies"
    },
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.EP",
      "subfield": "planetary"
    }
  ],
  "title": "Partial Fragmentation of Comet C/2025 K1 (ATLAS)",
  "title_text": "Partial Fragmentation of Comet C/2025 K1 (ATLAS)",
  "type": "preprint",
  "updated_at": "2026-10-30T12:35:35Z",
  "url": "https://research.draconitic.com/paper/3zxytsrcf0fdy",
  "venue": "arXiv",
  "versions": []
}